Panasonic U-72MF2U9 Service Manual page 187

3. 3WAY Alarm Codes
P22 Alarm
Alarm code P22
Alarm meaning Fan motor or inverter drive of outdoor unit has failure.
Alarm conditions Fan motor start failure, fan motor Hall IC input failure
Probable cause Possible causes are a Hall IC input circuit failure and a Fan PCB failure.
Check Check the fan motor wiring, the Hall IC wiring, and the connector connections.
If the wiring and connectors are normal, then measure the resistance between fan HIC power (P)
and ground (N) with the tester.
If there is a short-circuit, there is an HIC malfunction.
FAN PCB
(A747844)
Correction If the fan does not start, the below corrections may be effective.
(1) If there is a fan HIC failure or circuit failure, replace the FAN PCB.
(2) If the fan motor is locked, replace the fan motor.
Example —
Notes Turn OFF the power, and check the continuity of "P" and "N" on the FAN PCB.
P19, P29 Alarm
Alarm code P19, P29
Alarm meaning P19 : Inverter for 2nd compressor failed to start or failed to syncronize with rotation.
P29 : Inverter for 1st compressor failed to start or failed to syncronize with rotation.
Alarm conditions This alarm may occur at start, and occurs when open phase or lock is detected, and when a
DCCT failure occurs.
Probable cause Generally this alarm occurs when the refrigerant pressure balance is uneven at start, or when
inverter compressor lock occurs, there is an open phase in the inverter compressor wiring, or a
DCCT failure occurs. This can be judged to be starting trouble which is not caused by HIC.
Check Check the power wiring and connector wiring.
Correction DCCT failure (replace the HIC PCB) or compressor failure
Example —
P
5 - 25
3WAY VRF SYSTEM
Trouble Diagnosis
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